Hi all newbie here and need some help i have bought a used bradcott porch awning if anyone out there has one can you tell me how to get the base unit and extention in the awning rail and zipped up and not have a gap between the the two canvases at the top of the awning rail. I have put it up half a dozen times and still can't lose the gap it's now doing my head in. Cheers all.